picked up a camshaft a while back and its stamped "A3"  - anyone know if that means it's A3 steel?  a couple of pics for reference  ... thanks

 

I would suspect that is a part rather than a material identification but I couldn't confirm that. What are you intending to do with it?

I don't recall ever hearing of A-3 steel.

Likely a manufacturing batch number.

Do you stamp your tools with the ID of the steel gradeyou used ?  perhaps tool or maker ID, rarely does anyone other than the designer care about the grade of steel used. Even then the manufacturing process  means its subject to change due to availability.  Many times its the Q&A inspector stamp to prove it passed.

A3 Carbon steel is a category of Air Hardening Tool Steel.

A3 is composed of 1.25% Carbon, 0.5% Manganese, 5.0% Chromium, 0.3% Nickel, 0.9–1.4% Molybdenum, 0.8–1.4% Vanadium. The composition makes the alloy wear and corrosion resistant.